During the final assembly stages of many consumer products, including but not limited to appliances, automobiles, and the like, trim or finish pieces are commonly applied to the finished surfaces by inserting threaded fasteners through the trim or finish piece and into the finished surface. A worker typically applies these fasteners using various tools including screwdrivers, nut drivers, socket wrenches, and the like, or pneumatic or electric powered tools that drive various bits and/or sockets. These tools have hard metal surfaces, and in the case of screwdrivers or bits driven by power tools, for example, have relatively sharp or pointed edges that can easily mar the finished surface if they should slip off the fastener while it is being driven into place. Sockets, nut drivers and the like can also mar the surface if they contact it, especially while they are rotating during the installation or removal of a fastener. Accordingly, great care must be taken to ensure that the tool does not accidentally contact the finished surface and cause damage to it. This can occur, for instance, if the tool should slip off the fastener while it is being installed or removed, or if the rotating tool contacts the surface. The level of care required to avoid contact between the tool and finished surface can impair productivity, or inevitably lead to damage, especially in an industrial environment where a large number of fasteners may need to be installed in a relatively short period of time.
Moreover, workers using power fastener tools typically hold or loosely grip the rotating portion of the tool to support and guide it while they are installing or removing a fastener. When extensions are used between the power tool and the bit or socket or other fastener-engaging portion of the tool, the worker normally loosely places his or her hand around the extension to guide the tool. In torque sensitive applications, gripping of the rotating portion of the tool by the worker can result in incorrect torque application to the fastener. Further, because of this contact between the worker and the rotating portion of the tool, and the potential risk of the worker's hair becoming caught in the joint between attached components of the tool, such as, for example, between an extension and a socket, or between other joined together parts of the tool, injuries are not uncommon.
Conventional tools generally do not have any means to prevent contact between the hard metal surface of the tool and the finished surface, or between the worker and the rotating portions of the tool, although some efforts have been made in the prior art to solve the problem of marring finished surfaces. These efforts generally involve the provision of various cushioning devices or protective sleeves in association with the fastener-engaging portion of the tool. Examples of such prior efforts are disclosed in U.S. Pat. No. 5,009,133 to Carey (the '133 patent), and U.S. Pat. No. 6,138,538 to Neijndorff (the '538 patent), and in the nylon-coated, mar-resistant tools offered by Cooper Tools of Lexington, S.C., in its Apex® brand of fastener tools (the Apex® tool).
The '133 patent discloses several embodiments of protective sleeves that may be applied to the fastener-engaging portion of a tool, i.e., a socket, nut driver, screwdriver, or the like, to prevent contact between the hard metal of the tool itself and the finished surface, and these sleeves are designed so that there can be relative rotation between the tool and the sleeve. More specifically, the sleeve is described as having a relatively smooth inner surface that enables the sleeve to rotate on the tool, and a cushioning material on the end of the sleeve is designed to contact the finished surface and not move, i.e., not rotate, relative to the surface while the tool is rotating. In some embodiments, a ball bearing or other low friction cap is placed on the very end of the tool to function as the cushioning means, and in other embodiments a sleeve extends throughout the length of the socket or similar fastener-engaging portion of the tool and has an in-turned lip on its end that extends inwardly over the end of the tool to function as the cushioning means, or an o-ring or similar cushioning device is provided on the end of the sleeve to contact the finished surface. The '133 patent also suggests that the embodiment shown in FIGS. 11 and 12 can be held by a worker to support the tool while it is turning.
The nylon sheath in the Apex® tool is a coating applied to the socket or other fastener-engaging portion of the tool, and thus is fixed to the tool and turns with it. Similarly, the collar in the '538 patent is applied to an extension or to the socket or other fastener-engaging portion of the tool, and is fixed relative to the tool and turns with it.
The sleeves in the '133 patent are described as being made of a vinyl plastic or other similar resilient flexible material, such as rubber, and are disclosed as separately made and then applied to a tool. The collar in the '538 patent is disclosed as being either manufactured separately and then applied to a tool, or molded on the tool, and is further described as being made of a polymeric material having at least some elasticity, for example, an ABS elastomer, SAN elastomer, a polyurethane elastomer, or the like. Polymers such as polyethylene, polypropylene, and nylon are also disclosed in the '538 patent as useful. Other materials such as polycarbonate, polyacrylate, polyaramide, polyethersulfone, polysulfone, poletherketone, polyetherimide, polyimide, and the like are also disclosed as useful.
The collar in the '538 patent is applied only to the fastener-engaging portion of the tool, i.e., the socket or bit, and is intended solely to prevent marring of the finished surface. There is no suggestion of applying it to any extension, or covering any joints between connected parts, or making the tool rotatable in the collar so that the collar provides a non-rotating surface that can be gripped by the hand of the worker to guide and support the tool without having to contact a rotating part.
Similarly, and although the coating applied to the Apex® tool is shown as applied to both the fastener-engaging portion of the tool, i.e., the socket or bit, and also to an extension, the coating is fixed relative to the tool and thus does not provide a non-rotating surface that can be grasped by the user to support and guide the tool without having to contact a rotating surface.
The sleeve in the '133 patent is also disclosed as applied only to the fastener-engaging portion of the tool, i.e., the socket or bit, and is intended solely to prevent marring of the finished surface. The sleeve in this patent is designed so that the tool rotates in it, thus providing an exterior surface that does not rotate and that can be gripped by a worker to support and guide the tool, but there is no suggestion of applying it to any extension, or covering any joints between connected parts. Neither is there any suggestion of providing means to enable the sleeve to be gripped without affecting the torque of the tool, that is, absorbing some of the energy output of the tool and potentially resulting in inadequate torque being applied to the fastener.
Further, none of the protective coverings known to applicant extend over flexible portions of the tool, such as over swivel connections or adapters, or over flex shafts and the like.
Accordingly, there is need for a non-rotating protective sheath for a tool, wherein the sheath is effective to prevent marring of finished surfaces and also provides a non-rotating surface that can be grasped by a worker to support and guide the tool without affecting the torque output of the tool, that covers connections or joints between connected parts of the tool, and that covers flexible portions of the tool, such as flex shafts, swivel connectors and adapters, and the like.